#include<stdio.h>
#include<string.h>

int main()
{
	char str1[50], str2[20];
	int i, j = 0;
	printf("Please input the string NO.1:\n");
	gets(str1);
	printf("Please input the string No.2:\n");
	gets(str2);
	for (i = 0; str1[i] != '\0'; i++);
	while ((str1[i++] = str2[j++]) != '\0');
	printf("string NO.1:\n%s\n", str1);
	return 0;
}
